What Have Studies Shown About Cohabiting Couples,when Compared with Legally

What have studies shown about cohabiting couples,when compared with legally married ones?

A) Cohabitors are less likely to separate or divorce.
B) Cohabitors are more likely to separate after five years of marriage.
C) Cohabitors are more likely to separate if they cohabited more than once.
D) Cohabitors are more committed when they eventually marry.